Author Question: Instructions: Refer to the data below to answer the following question(s). Porcine dynorphin is ... (Read 67 times)

kshipps · **on:** Aug 23, 2018

Instructions: Refer to the data below to answer the following question(s).

Porcine dynorphin is a neuropeptide having 17 amino acid residues. Its structure is shown below.

Tyr-Gly-Gly-Phe-Leu-Arg-Arg-Ile-Arg-Pro-Lys-Leu-Lys-Trp-Asp-Asn-Gln
Refer to instructions. What fragments would result if dynorphin were cleaved by trypsin?

Question 2

Write the equation for the reaction, using methanol (CH₃OH), that would render the carboxyl group of alanine unreactive.

Question 3

Instructions: Consider the following structure. Based on this structure answer the following question(s).

Refer to instructions. How many other peptides could be formed from this same combination of amino acids?
a.
3
b.
6
c.
9
d.
12

Question 4

Instructions: Consider the following structure. Based on this structure answer the following question(s).

Refer to instructions. Name the peptide using both the three-letter and one-letter codes.

Question 5

Instructions: Consider the following structure. Based on this structure answer the following question(s).

Refer to instructions. Circle the peptide bonds.

Question 6

Instructions: Consider the following structure. Based on this structure answer the following question(s).

Refer to instructions. Identify the C-terminal amino acid and the N-terminal amino acid.

Question 7

Instructions: Refer to the data below to answer the following question.

Amino Acid
Isoelectric point
Arginine
10.76
Glutamic Acid
3.22
Tryptophan
5.89

Define isoelectric point.

chloejackso · **Reply #1 on:** Aug 23, 2018

Answer to Question 1

Trypsin catalyzes the hydrolysis of peptides as the carboxyl side of arginine and lysine. Consequently, the fragments resulting from trypsin hydrolysis of dynorphin are:

Tyr-Gly-Gly-Phe-Leu-Arg

Arg

Ile-Arg

Pro-Lys

Leu-Lys

Trp-Asp-Asn-Gln

Answer to Question 2

Answer to Question 3

b

Answer to Question 4

ANS: Ser-Phe-Gly
S-F-G

Answer to Question 5

Answer to Question 6

Answer to Question 7

The isoelectric point is the pH at which an amino acid is exactly balanced between anionic and cationic forms and exists primarily as the neutral, dipolar zwitterion.